/Engine/Source/Runtime/Engine/Classes/Particles/ParticlePerfStatsManager.h
Controls whether this listener should be stooped and cleaned up when it's orphaned, i.e. the manager is the only one with a reference. In some cases we want to signal that a listener should stop by clearing an external reference. In other cases we want to have fire and forget listeners that can signal their own termination via their tick function.
virtual bool AllowOrphaned() const